From patchwork Wed Sep 14 11:11:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?w43DsWlnbyBIdWd1ZXQ=?= X-Patchwork-Id: 12976022 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B726ECAAD8 for ; Wed, 14 Sep 2022 11:11:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229632AbiINLLx (ORCPT ); Wed, 14 Sep 2022 07:11:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbiINLLw (ORCPT ); Wed, 14 Sep 2022 07:11:52 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7543B5E643 for ; Wed, 14 Sep 2022 04:11:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663153910; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=kX+pi/HvCDp+oQlA12cx7MP2R0GtvFwa5Le5qJ2HSwg=; b=Y9i1ua/44Z0uoNLPi5k3fMsAhgG2/US2gfx0HHclxIkdPN2l+CYD2WOHQSxPM0R2KdnWIW zZfNVd77oo5jABt8YgzLhXzF94WT7Zjo/eSymkrMVhq0KLPbV0u8cpMAg+F9W1mhHVIbJw KRmUVMR71AZSuO8kaUiNkc7kdDQ98QI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-372-LTLFTFDuMkmlSLn1A2rf2w-1; Wed, 14 Sep 2022 07:11:40 -0400 X-MC-Unique: LTLFTFDuMkmlSLn1A2rf2w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9531A3C025C7; Wed, 14 Sep 2022 11:11:39 +0000 (UTC) Received: from ihuguet-laptop.redhat.com (unknown [10.39.195.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id E81791759E; Wed, 14 Sep 2022 11:11:37 +0000 (UTC) From: =?utf-8?b?w43DsWlnbyBIdWd1ZXQ=?= To: ecree.xilinx@gmail.com, habetsm.xilinx@gmail.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, =?utf-8?b?w43DsWlnbyBIdWd1ZXQ=?= , Tianhao Zhao Subject: [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit Date: Wed, 14 Sep 2022 13:11:35 +0200 Message-Id: <20220914111135.21038-1-ihuguet@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Trying to get the channel from the tx_queue variable here is wrong because we can only be here if tx_queue is NULL, so we shouldn't dereference it. As the above comment in the code says, this is very unlikely to happen, but it's wrong anyway so let's fix it. I hit this issue because of a different bug that caused tx_queue to be NULL. If that happens, this is the error message that we get here: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [...] RIP: 0010:efx_hard_start_xmit+0x153/0x170 [sfc] Fixes: 12804793b17c ("sfc: decouple TXQ type from label") Reported-by: Tianhao Zhao Signed-off-by: Íñigo Huguet Acked-by: Edward Cree --- drivers/net/ethernet/sfc/tx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index d12474042c84..c5f88f7a7a04 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -549,7 +549,7 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb, * previous packets out. */ if (!netdev_xmit_more()) - efx_tx_send_pending(tx_queue->channel); + efx_tx_send_pending(efx_get_tx_channel(efx, index)); return NETDEV_TX_OK; }